deps: backport String::Utf8Length with isolate

This overload was added in V8 6.9 and the one without the isolate
parameter was removed in V8 7.0.

Refs: https://github.com/v8/v8/commit/3dd5c6fe38355b8323597341409b37f931de5a85

PR-URL: https://github.com/nodejs/node/pull/22531


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>